Apparatus for immersing edge portions of black plate in successive treating baths



NW 2, 1943 w. M. ToMKlNs ETA-1 Y APPARATUS FOR IWERSING EDGE P ORTIONS 0F BLACK PLATE IN SUCCESSIVE TREATING 'BATHS 8 sheets-sheet 1 Filed Aug'. 9, 1943 NOV 2. 1948 w. M. 'roMKlNs ErAL 2,452,879

APPARATUS FOR EMMERSING EDGE PORTIONS 0F BLACK PLATE I SUCCESSIVE TRBATING BATHS 8 Sheets-Sheet 2 Filed Aug. 9, 1943 ING BATHS Q Sheets-Sheet 3 QW J DGE PORTIONS 0F W. M. TOMKINS ETAL APPARATUS FOR IHMERSING E BLACK PLATE IN SUCCESSIVE TREAT Nov. 2, 1 948.

Filed Ag.' 9, 1945 N .NI @RRR W. M. TOMKINS ETAL PARATUS FOR` IMMERSING EDGE PORTIONS BLACK PLATE IN SUCCESSIVE TREATING BATHS 8 Sheets-Sheet 4 NN N .QN Sm WNW Nov. 2, 194s.

Filed Aug. 9, 1945 2,452,879 OF HS 8 Sheets-Sheet 5 NW 2, 1948 w. M. ToMKlNs ETAL I APPRTUS FOR IHMERSING EDGE PORTIONS BLACK PLATE IN SUCCESSIVE TRETING BAT Filed Aug. 9. 1943 NOV 2. 1948- w. M. ToMKlN's Erm.

APPARATUS FOR IIIERSING EDGE PORTIONS OF BLACK PLATE IN SUCCESSIVE TREATING BATHS Filed Aug. 9, 1943 8 Sheets-Sheet 6 Nav. 2, 1948. w.4 M. ToMKlNs ETAL 2,452,879

v APPARATUS FOR IMMERSING EDGE PORTIONS QF Y BLACK PLATE I SUCCESSIVE TREATING BATES Filed Aug. 9, 1943 8 Sheets-Sheet 7 w ia if W. M. TOMKINS ET AL Nov. 2, 1948. 2,452,879

APPARATUS FOR IMMERSING EDGE PoR'rIoNs oF BLACK PLATE IN s Hs Filed Aug. 9. 1943 UCCESSIVE TREATING BAT 8 Sheets-Sheet 8 emm e%%% www d wwwmw ww www l Llul S h, Lsm

Patented Nov. 2,

APPARATUS FOB IMMERSING EDGE POR- PLATE IN SUCCESSIVE TIONS F BLACK TREATING BATES Waiter M. Tomkins and Albert C.

St. Charles, Montreal, Quebec, Anthony and Oakland K. Ross,

Canada, and Ralph M. Mero, Chicago,

Quebec,

Larkin, Pointe and John C.

St. Laurent,

Ill., assignors to Continental Can Company,

Inc., New York York, N. Y., a corporation off' New Application August 9, 1943, Serial No. 497,982 In Canada August 3, 1943 'y .This invention relates to appara-tus for preparing black plate blanks, especially bonderized plate blanks, for the formation of can bodies having solder-bonded side seams. Diiliculty has been .encountered in the forming of solderbonded side seams of can bodies made from'black plate because the plate stock, when exposed to air, oxidizes and forms a scale which interferes with the soldering of the sideseam. IAccording to the present invention, the edge portions of plate blanks to be formed into side seams are,

cleaned, preferably catho'dically, and are then coated or plated with a material, e. g. tin, which is resistant to oxidationand which has an amnity for a solder bond.

An object of the invention isl to provide a apparatus for simultaneously treating or pre-v paring the edge portions of a group of individual blanks simultaneously. Y,

Another object of the invention' is to provide new ,and improved means for releasably clamping blanks and supporting them on a conveyor.

Another object is to provide novel apparatus "I i'or transferring blanks or groups of vblanks from one conveyor to another.'

Another object of the invention is to provide l mechanism for reversing the position of blanks carried by `treating conveyor mechanism so that E IV-IV;

apparatus for the handling and treatment of blanks of diierent sizes.

Other objects of the invention will become apparent from a reading of the following description, the appended claims, and the accompanying drawing. l y

In the drawings:

Figure 1 is a ilow diagram indicating schematically the sequence in which the steps may be performed in practicing the method;

f Figure 2 is a, vertical sectional view of enameling apparatus;

Figure 3 is a perspective view of a prepared blank; x,

,Figure la` isa 'somewhat diagrammatic front elevation of apparatus embodying the invention inane form showing portions of the apparatus on one side of a, line IV-IV;

Figure 4h isea view similar to Figure 4* butlc' showing apparatus on the other side of the line IV-IV, it being intended that Figures 4b and 4' be read together as if Ajoined along the line Figure 5`is an elevation of one form of gripping means for releasably holding a group of blanks on a conveyor, guides or tracks for the conveyor being shown in section;

Figure 6 is a plan view of the gripping means shown in Figure 5 as viewed when looking in the direction of the arrow 6 in Figure5;

Figure '7 is an elevation of a second form of gripping means assembly;

Figure 8 is a section on the line 8-8 of Figure '7. Figure `9 is a detail section on the line 9-9 of Figure 7, drawn on an enlarged scale; i

Figure 10 is a detail section on ,the line I0|0 l of Figure 7, drawn on an enlarged scale;

Figure 11 is a detail section on the line ll-ll of Figure '7, drawn `on an enlarged scale;

Figure 12 is a fragmentary plan view, on an enlarged scale, of a pusher bar equipped with guide clips for receiving the trailingy edges of opposite edge portions of the blanks may be presented in turn for treatment.

Another object of the invention is to provide means for `moving blanks edgewise through a treating bath. l

A further object of the invention is to provide apparatus of the character referred to in which adjustments can be effected for adapting the blanks carried by the gripping means shown in Figures 7 to 11 inclusive;

Figure 13 is a fragmentary top plan view, on an enlarged scale, showing the mounting of a pusherJ bar hanger as viewed when looking in the direction of the arrow I3 in Figure ,'Z.

Figure .14 is an elevation of a third-form of gripping means assembly;

- 3 Figure 15 is a plan view in Figure 14 as seen when looking in the direction of the arrow I in-Flgure 14. j f

, Figure l16 is a detail section 'on the line Il--IS of Figure 1,4, drawn on an enlarged scale;

Figurel'l is a diagrammatic perspective view' showing a plurality of grouped blanks being moved through a treatingbath; and

Figure 18 is a. fragmentary elevation of cam and lever mechanism for operating a blank gripper actuating cam, a drive shaft being shown in section.

A preferred sequence in which a series of operations maybe performed in preparing individual blanks for the formation ofcan body solder bonded side seams is indicated schematically in Figure 1. A ribbon or web I of black plate stock which has been bonderized, i. e.. coated with zinc phosphate,'is drawn by suitable rolls 2 through an enameling apparatus generally designated 8 for coating both sides of the .web I with enamel but leaving 'marginal portions at each side of the blank bare or unenameled. The

enameling apparatus t includes a first tank 4 containing enamel indicated at II, a transfer roll 8 and an applicator roll 1 for applying enamel to one flat surface of the web I. The apparatus 3 further includes a second tank 8 containing enamel 9 adapted to be picked up by a transfer roll 'I0 and supplied to an applicator roll Ii arranged to apply enamel to the opposite fiat surface of the web I. As shown in Figure 2, the web edge portions a: and y extend laterally beyond the applicator rolls 1 and II so as not to be coated with enamel.

After leaving the drawer roll 2 the web I passes through an oven or drying apparatus indicatedv at i2 and which maybe of any conventional or suitable form, and then passes to a shear or other suitable severing means indicated at I3 for cutting off individual plate blanks I4. later to be formed into can bodies. It is apparent that although the enameling of a continuous web followed by the cutting ofi! of individual plate blanks i4 provides for rapid operation, the enameling of individual blanks after they have been cut to size would provide equivalent results since in either case the individual blanks would have corresponding enameled' surfaces and unenameled edge portions. The specific apparatus employed and procedure followed in enameling the `blank material is not of particular importance.

In accordance with the invention. the blanks are moved to a treating bath and the lower edge portion only of each blank is projected into treating fluid, the blank then being withdrawnfrom the fluid, reversed, and the other unenameled edge portion is projected into the fluid for similar treatment. Preparatory to treating each blank in this'manner, it is placed vertically as indicated at I4* in Figure 1. The blank is then moved over a treating bath container I5 and is projected downwardly to the position indicated at Hb so that the unenameled lower edge portion y is immersed in a cleaning fluid i6,-the line of demarcation between the unenameled edge portion u and the enameled portion of the-blank being substantially at/the level ofthe fluid I6. The blank may then4 be moved horizontally through the fluid I8 while the cleaning operation is being performed. The blank should be moved edgewise so as to cut through the `fluid without creating waves, ripples or other disturbances. In this way the level of the fluid I8 will not rise and fall above the line of demarcation between the ofthe assembly shown I unenameled edge portion il and the enameled part'of the blank. Consequently, the cleaning fluid will not attack the enamel.

In accordance with a further feature 'of 'the 5 invention, aA plurality of blanks are moved in a group through the treating fluid. I 8, the grouped arrangement of the blanks being such thatall 'of the individual blanks move edgewise through the fluid. Figure 1. which is schematic. shows 1o only one blank Il, but it will be understood that in practice it is advantageous to move a plurality of grouped blanks through the treating fluid. As will be explained in the description of a preferred form of apparatus, the groups advantageously may 'comprise six blanks as shown in Figure 17.

The moving of the blanks edgewise is particularly advantageous when the blanks are treated in groups. It will be apparent that if in the treatment of 4a group of blanks the blanks were to zo move iiatwise, the waves or ripples created by one or more ofthe blanks would raise into contact with the enamel portion oi' other blanks, thereby harming the enamel coatings.

The cleaning oi.' the unenameled edge portions preferably is accomplished cathodically. For this purpose an anode I'I is immersed in the fluid I8 and the blank I4 is arranged to make contact with a bus bar I8. The anode il and bus bar I8 are ladapted to be connected to a source of current by means of conductors I8. 'I'he electrolyte or fluid I 8v preferably comprises a ten percent to fifteen percent sulphuric acid bath at room temperature, e. g.. 70 to 80 F. The liberation of hydrogen on the unenameled edge portions y mechanically aids in loosening the phosphate film which is dissolved in the acid bath solution.

The blanks may travel approximately three feet through the cleaning liquid during an immer- 40 sion period of about ten'seconds, that is, at a rate oi' three-tenths foot per second. 'Ihe path of travel through the fluid need not be exactlythree feet because the times during which the blanks are being lowered into the liquid and are being raised from the liquid are to be added to the time during which they travel horizontally in order to determine the total treating period. A

net treating period of ten seconds is preferred.

and, therefore, the horizontal travel may be someilo what less than threeA feet. Application of a E. M. F. of three volts to the anode I'Ifand bar I8 will produce a current of about thirty amperes.

After the cleaning of the unenameled edge porition y each fblank is withdrawn from the fluid 13.-', I8. It is not necessary to remove cleaning fluid adhering to the blanks after withdrawal fromthe cleaningv fluid-but some saving of cleaning fluid may be effected by mechanically removing the adhering fluid by the use of squeegee rolls or other suitable means.

When the blank has been removed from the cleaning fluid I8 its edge portion y will be clean and unencumbered, the "bonderized" coating having been'removed, The blank is then moved over a plating tank or container 20 and lowered so as to project the edge'portion y intov plating iiuid 2l, the blank then being in the position indicated at I4 in Figure i.

The edge portion y then is plated with anoxidation resistant materiau having an afilnity j, for a solder bond. Several ways of forming such a plating are known. For example, in United States Patent 2,304,931 to Kronquest, blank edge portions are prepared for forming solder bonded side seams by being diDDed in copper sulphate s solution. According to the present invention it is preferred to electroplate the blank edge portions with tin. The electrolyte 2| in the tank 2l may lcomprise the following' constituents substantially` in the proportions indicated:

. Ounces Tin (stannous) f 4- 5.6 "Free sulphuric acid 6.4-112 Cresol sulphonic acid \..f .11.2-19.3 Gelatine V3 Beta-naphthol lf@ Water (distilled) to make 1 gallon An anode 22 preferably of pure tin is immersed in the electrolyte 2|. .A busbar 23 is arranged to be in electrical contactwith the'blank during the electroplating operation. The anode 22 and bus bar 23 are adapted to be' connected to la source of current by conductors 24.

During the electroplating operation the blank or blanks are moved edgewise through the fluid 2| the same as was done during the cleaning operation.

The cresol sulphonic acid acts as a solution stabilizer and prevents atmospheric oxidation'.

The gelatine and beta-naphthol are additionalA agent for providing tin deposits which are smooth and bright and have good covering qualities. f

- The temperature of the plating bath. as well as the immersion period and travel of the bodies in the bath are the same as for the cleaning bath. 'Ihe plating time is approximately ten seconds with a current of 1.5 volts and 16 ampheres, and the anode current densityv is about 4.5 ampheres per square-foot.

The average thickness of the tin coating' de-l termined from a number of samples is'found to be .000027 inch'.

After the cleaning and treating ofthe blank lowergedge portion y, the blank is reversed or inverted so as to be in the position indicated at Md in Figure l, with the edge portion c at the bottom. This edge portion is then treated in a cleaning tank 25 containing fluid 26.

nected by conductors 29 to a source of current. After the edge portion :c is cleaned, the blank is moved to the position indicated at |4f. The edge portion a: is within a tank 30 and immersed in plating fluid 3|.: A tin electrode 32 and bus bar 33 are adapted to be connected to a source of current by conductors 34. After the edge portion :c has been plated the blank is withdrawn, `a blank |4 with both edge portions :z: and y cleaned, plated, and ready for the formation `of a container body side seam lbeing indicated at |42.

- Figures 48 to 1'6 inclusive disclose apparatus embodying the invention and suited for practicing the hereinabove described method rapidly. Considered in its general nature the disclosed apof a transfer conveyor generally designated C.

The conveyor C is equipped with means later to be described for simultaneously picking up the blanks I4 of a group of six blanks, and moving them to the position indicated at 35 in Figure 4a for transfer to a lower treating conveyor D. The conveyor D receives the blanks from the transfer A lead 45 anode 21 and bus bar 28 are adapted to be con-` conveyor C and carries them in groups suspended from itslower stretch to move downwardly at 38 for. projecting the blank .lower edge portions into the cleaning bath tank. l, then raising the blanks 5 and thereafter again lowering the blanks as at 31 for projecting their bottom edge portions into'v the plating tank 20. The blanks then move on to the transfer position indicated at 33 where 'they are. released from the lower treating conveyor and picked up on an upper treating conveyor E positioned above the conveyor D. When this transfer has been eected, the blank edge portions which were treatedin the tanks I5 and 20 will be held by the upper treating conveyor E so as to leave the oppositeedge portions extending downwardly, the blanks having thus been with the lower stretch of the conveyorE to follow the path indicated in Figures -4 and 4b until moved downwardly as at 38 so as to have their bottom edge portions projected into cleaning fluid in the tank 25. After passing beyond the tank the blanks again are lowered as at 40 for having their lower edge portions projected into the'plat- 25 ing bath in the tank 30. After being xnoved through, and raised clear of the tank 30, the blanks move on to a point'of discharge indicated at 4| in Figure 4B. g

The mechanism A for effecting initial feeding of the blanks is adapted to take or receive individual blanks successively from the bottom of a stack held, for example, by a magazine (not shown), the bonderized blanks |4 held in the magazine having previously been enameled with the exception of opposite edge portions .'c and y. In operation a group of six blanks received by the conveyor B will be moved to the top stretch and will be positioned as indicated at |4 in Figure 4&5 Thewblanks of the group will be ldisposed in mutually 'parallel planes.`

When a 4group of six blanks has reached thev position I4,- the conveyor B is stopped and the group of .blanks is moved transversely of the direction of conveyor movement, that is to the right as viewed in Figure 4B for being picked up and carried away by the transfer conveyor C.

The transfer conveyor mechanism C includes three perau'ei shafts |22, |23 and |211 mounted to rotate on bracketssecured'to the frame. The shaft |22 carries a pair of spaced sprockets |21, the shaft |23 carries a pair of similarly spaced sprockets |28. and the shaft |24 has secured thereto in similarly spaced relation a pair of drive sprockets |29. Conveyor chains |30 are trained respectively one around each complement of spockets |21, |28 and |29. -A plurality of blank gripper or releasable holding assemblies |3| is carried by the spaced chains |30, the gripper assemblies |3| being spaced from each other along the chains |30. When a gripper assembly |3| is opposite the conveyor C the blanks |4 of a group are presented to the conveyor C. ,Thereafter the gripping assemblyv is operated to grip or hold the blanks and'move them around for delivery to the bottom treating conveyor D. The conveyor C is stopped when each gripping assembly reaches the proper position so that the thus positioned gripping assembly will be at rest when it receives the group of blanks |4 presented by the conveyor B. The gripper mechanism |3| previously referred to only `generally is shown on an enlarged scale inyFigures 5 and 6. yIt includes a cross frame inverted or. reversed. The blanks move along member |55 equipped at its ends with angle brackets |54 f or connection respectively to the chains |50 of the conveyor C. A plurality of fingers |55 spaced from each other correspondingly to the spacing of the blanks of a group is secured to the frame |53 as at |56. An actuating rod or bar |51 mounted to slide through the fingers |55 carries a plurality of similarly spaced fingers |58 movable with the rod |51 relatively to the xed fingers |55.v Rubber pads |55 mounted on the movable fingers |58 respectively are adapted to engage blanks positioned between each pair of lingers |55-|58 to clamp the engaged .blanks against the associated ilxed :lingers |55.

`A spring |50 is interposed between the movable finger |58 shown at the left in Figures 5 and 6 and a collar on an adjusting screw |52 carried bya bracket |53 secured to the bar |55 by a screw and nut |55-|65. 'I'he spring |50. constantly urges the bar |51 toward the right so as to movethe gripper fingers |58 into gripping position. For opening the grippers to condition the grippers to receive blanksl a roller |55 is Journalled on the frame |55 as at |51 and a roller |55 is journalled on the bar |51 as at I 55. Normally the rollers |55 and |58 are in the positions shown in Figures 5 and 6. A wedge cam |10 is adapted to move relatively between the rollers |55 and |58. The roller |55 cannot move longitudinally of the rod |51 and therefore entry of the cam between the rollers will move the roller |55 and the rod |51 against the urge of the spring |50 so as to open the griDDers.

The gripping devices Ill mounted on the conveyor C are adapted to be operated in time 'with the operation of the feeding device B, the arrangement being such that when the gripping mechanism is in a receptive position, the grippers will all be open and thus will be conditioned to receive blanks I4 pushed toward the conveyor C. Insertion of the blanks into the open grippers isv facilitated by rounded edges |1| on the fixed gripper parts |55. After the blanks have been inserted and while theconveyors B and C arel l still at rest.- the cam |10 is withdrawn from between the rollers |55 and |55 so as to permit.

the spring |55 to move the rod I 51 and close the grlppers. Then the conveyor C is driven through A 8 cam |10 which then Will be held stationary in its upper position by the cam |53 and lever |15. Continued movement of the rollers |55 and |55 while the cam |10 is stationary will cause the roller |58 to move longitudinally of the assembly |5|, thereby opening the grippers and conditioning the gripper assembly to receive a group of blanks being fed to it.

The group of blanks is fed into Ythe open grippers on the assembly 15| while the cam |10' is still held in its upper position. When the blanks are in the grippers the cam |55 will move o n around to permit the spring |85 to rock the lever |15 and move the rod |12 downwardly. This will withdraw the cam |10 from between the rollers |55 and |58 on the assembly |5|,`and the grippers will be closed by the spring thereby clamping the group of blanks to the transfer conveyor C.

The treating conveyors D and E are mounted on a frame and are driven continuously in 'synchronism with each other and at a speed corresponding to the uniform velocity driving speed of the transfer conveyor C. The conveyor D is trained around sprockets 55 shown at the left in Figure 4 and around sprockets |51 and a drive sprocket |58 shown at the right in Figure 4b.

The conveyor D is driven by gearing interposed between the shaft 51 and the sprocket |88. A bevel gear I 55 on the shaft 51 meshes with a gear |50 fast on a shaft |8I. A sprocket |82 on the shaft 5| is connected by a chain |55 with a sprocket |54 fast on one end of a shaft |55 v(seegears |55 and |51 together with the sprocket |55 for varying the tension of the conveyor D.

The conveyor E is trained around a drive sprocket |85 shown at the left'in Figure 4 and around sprockets |55|55 and 200 shown at the the mechanism |52 previously described and' after the blanks carried by the grippersl are raised above the arms on the conveyor B. the'.

latter is driven again through the intermittent drive mechanism.

The cam |10 must be moved relatively tothe rollers |55 and |55 carried on the `conveyor C while the conveyor is at rest. Any suitable means may be provided for mounting and moving the cam |15; for example, the cam may be mounted on a rod |12 extending vertically between'the 'conveyors B and C. through a guide |15 carried The lower end of the rodby a frame shelf |15. |12 is pivoted as at |15 to a link |15 in turn Apivoted at |11'to onearm of a lever. |15 pivoted at |15 on a bracket |55 carried by the fram base t right in Figure 4P. and is driven by gearing interposed -between the shaft |55 and the drive sprocket |55. As shown in Figure 4* a sprocket 20| fast on the shaft |55 is connected by a chain 202 with a sprocket 255 secured to a shaft 205'. The shaft 25s is equipped with. a bevel gear 205 meshing with a bevel gear 205 which lis connected to the drive sprocket |55.

-Both conveyors D and E are equipped with grippers similar to the grippers, |5|Apreviously described with .reference to theA transfer conveyor C. However. the gripperscarried by the conveyors D and E should be' insulated from the conveyor chains on which they are mountedand for this Purpose the gripper 'frame elements |55 may comprise insulating blocks indicated at 2I5 in Figures 5 and s.

The operation of the transfer conveyor C and bottom treating conveyor D is so timed that when a group of blanks reaches the position indicated at 55 lnlllgure4lthe blanks willbe mppe'dby the gripper on the conveyor D and then will be taking place while the conveyors are traveling st the same speed. Inasmuch as the l'rippers are .operated during movementof the conveyors, the

cams for entering relatively between -the rollers 55 and. |55 are mounted respectively in iixed positions on the vframes carrying the conveyors l C and D. .The relative positioning o! the cams t mueve ,for effecting thel properly timed releasing and in Figure 4*. wherein a cam shown at 2 I4 is positioned to open grouping of the blanks is indicated .the grippers on the conveyor D and to then permitthegrippers toclose just before a cam shown at 2|5 opens the grippers carried`by the transferl conveyor C.`

Blanks held on the vConveyor D are treated suc'- cessivelyA in the tanks I6 and 28 and are then noved' up to the transfer station indicated at 88 in Figure 4b where they are transferred to grippers carried bythe lconveyor E. The gripperson.

' the conveyor E also may conform to the construction shown in Figures 5 as indicated at 2I6 is adapted to'enter relativeand 6.y A cam positioned 1y between the gripper operating rollers`|88 and |68 for conditioning'the grippers to receive blanks when the grippes arrive at the transfer station 38. A cam positioned as indicated at 2|1 is adapted to engage the rollers |66 and, |68 of a gripperl assembly carried by the conveyor D for openin'g. the grippers on the conveyor D after;

l extended downwardly for treatment in the tanks 26 and 30.

When blanks carried by the conveyor E have been treated and moved beyond the tank 36, the Aassociated gripper operating rollers |66 and |68 will move' into engagement with a cam positioned as at 2|8 in Figure 4l so that the grippers will be opened and the blanks released at the discharge station 4 I.

Returning now to the treatment of blanks carried on the conveyorD, a bus bar I8 mounted above the cleaning tank I5 is adapted to engage the gripper frame` |53 as a group of blanks ispass'- ing along the tank I5, so as to establish a circuit including the bus bar I8, gripper frame |53, the

blanks I4 and the anodes I1. Preferably, insulated' wires 2|il.` extending 'in the direction of blank travel through the tank are provided for guidingthe blanks and maintaining them against lateral sway. When a group of blanks has been withdrawn from the fluid in the tank I5, the treated lower edge portions of the blanks pass between p-airs of squeegee rollers 228 for removing adhering cleaning fluids -1 The blanks then pass on for having their lower edge portions plated in the tank 20. Associated withthisv tank is the bus bar 23, anodes 22, i-nsulatedr guide wires 22| and squeegee rollers 222.

for removing adhering electrolyte.

While the blanks are ytraveling along the lower stretch of the top conveyor E, their lower edge portions are treated successively 'in vthe tanks 26 and 30. Associated withthe tank 26 is the bus bar 28, anodes 21, a s et of insulated guide wires. 223 and squeegee rollers 224. Similarlyassociated with the tank 30 is' the bus bar 33, anodes 32, a set of insulated guide Wires 225 and squeegee' rollers 226.

It will be apparent that the lbusbars,` anodes, guide wires and squeegee rollers associated rey spectively with each of the tanks 28, 26 and 30,

Mechanism is provided for` varying the spac' e f I ving between the carriers C and D so as to adapt the apparatusfor handling. and treating canbody L blanks of different lengths. In thev formshown.

thesprockets |88 engaged, bythe conveyor D ,are carried respectively by spaced sliders 221 and 228 mounted in guides 228 and 230 on the frame |84, The ,sliders-221, and 228 are adjustable towards and away from the conveyor C by screws, one of which is indicated at 23| in Figure 4*- The screw may be operated by a bevel gear couple 232 and an actuating shaft 233. y

The right hand end of the bottom conveyor D also is mountedfor movement toward and away from the conveyor E at the transfer station indirespectively on sliders 234, and 235 adapted to move vertically vin framel guides 236 and 231. lAdjusting screws, one of which is shown at 238, may be provided for raising and lowering the 20. sliders 234 and 235. The screw 238 may be rotated for adjustment by a bevel gear couple 239 and an actuating shaft'248. .v

-The tension of the bottom'treating Aconveyor D may be adjusted by shifting the sprocket |88 Y horizontally. The sprocket |88 may be mounted on a slider 24| adapted-to be shifted horizontally by a screw 242 rotatable by a bevel gear couple m and an actuating shaft zu.

The tension of the top treating conveyor E may be adjusted by. shifting the sprocket 280 'horizontally. As indicated in Figure flb the sprocket 200 may be journalled on a slider 245 shiftable horilzontally by a screw 246 adapted to be rotated by f a bevel gear couple 241- and' an actuating shaft 248. v

Each of the tanks I5, 2U, 26 and'38 is mounted for vertical adjustment to adapt the apparatus for the treatment of blanks of different' lengths. The mechanism for'adjusting thetank 30 includes a plurality of adjusting screws 249 journalled in brackets 250 carried by the frame |85. The screws 249v have threaded engagement with y mtericriy threaded s1eeves. 25| fast with thetank 30. Bevel gears 252 are rotatable by adjusting f'shafts 253 for' rotatingthe screws -249 and thus raising and loweringthetank 30.

The tanks I5, 20 and 26 are adapted to be adjusted vertically by mechanism the same as that shown for adjusting the tank 30.

Figures 7 to 13 inclusive show a modified blank gripping and holding unit which may be usedin place of the unit- |`3| described with reference to Figures 5 and 6. The modiiied construction comprises a cross frame or barI 255 fitted at its tively tothe conveyor chain |30 by angle brackets 251. The gripper assembly 254 is indicated as connection with the conveyor C it is not necesjsary to insulate the cross frame member 255 but when used on the conveyors D and E, thecross:

frame member should be insulated from the conveyor chains and for this purpose the end blocksV 256 may be constructed of insulating material.

L-shaped gripper parts 258 are secured to the frame 255 by screws 259 and are spaced correspondingly to the spacing of the blanksof a group of blanks to be treated. Eachy L-chaped part 258 includes a clamping face 268, and a guide portion 26| adapted to direct a blank into face to face cated at 38. The sprockets |81 are mounted opposite ends with blocks 256 connected respecthe gripper assembly also may be mounted on relationship with ythe -clampingportion f26| .of an adjacent part 255. Roundededge portions 290n and 25|* on the clamping faces 260 and the guide portions 29| further assist-in guiding the blanks between adjacent .parts 258.

An actuating rodi' 262 is mounted to .slide through the i..shape'd parts 258 and is i'ltted with angle pieces 253 each having secured to it a pair yci' rubber blocks 28|.held inplace by screws'255 and plates 285. Movement o! the rod 262 toward the left .as viewed-in Figures '1 and 8 shifts each pair of blocks 264 away kfrom the associated clamping face 260 on the` adjacentpart4 259-so as to condition the grippers to receive the blanks.

In order to Ihold the blanks on the gripping assembly 254. the rod 262 is shifted towardthe right whereby the blocks 284 will press the blanks against the respectively associated faces 260.

The rod 262 is urged toward theright by a spring 286 interposed between a collar 251 fast with'the lrod 282 and a socket 268 which is exteriorly threaded and mounted in an interiorly threaded lug 269. The tensiony koi the spring 266 may be adjusted by rotating the socket269Y ably. the laces 283 and 2.09 have7 curved blank s as at 292.` Each gripper element'290 comprises f with respect to the legs ofthe lever, spacers 299 an angle piece`293 and a pair of rubber blocks 294 secured to the angle piece by screws 295 and y.plates 296. lThe levers are arranged to be operated in unison by a link 291 pivoted to' the levers as at 298. beingU-shaped; and, for centering the link 291 may be interposedbetween lthe' sides .ofthe link The levers 29| fare shown as and the legs of the lever. Springs300 connected between the pivots 292 and 298 associated with 'each lever 'urge the levers to rock in a direction' to. move the associated lclamping blocks 294 toward the clamping faces 2890i' the respectively adjacent fixed clamping members'283, Thus the springs n300 tend to move tle gripper devices 290 into gripping position. y Mechanism for moving the grippers to open position includes a roller Journalled as at 302 nailed as at 214 on the shiftable rod 262, The

roller 213 and the rod 262 are adapted to be shifted by a wedge cam similar to the cam |10 which operates the rollers vIBB and |68 in the embodied shown in Figures 5 and 6.

The gripper mechanism 254 is equipped with means for pushing against the trailing edges of blanks held by the grippers 258-264. A pusher bar 215 is suspended from the frame 25E by Vhanger arms 215. Guide clips 211 secured to the pusher bar'218 are spaced correspondingly to the grippers so as to receive the trailing edges ci blanks held by the grippers, thereby maintaining the blanks parallel to each other andy holding them against shifting in the grippers. Preferably the arms 216 are adjustable on the frame 255. For this purpose the arms 216 are secured respectively to angle brackets 219 by'screws 280, and the angle brackets 219 are formed with slots 28| for accommodating clamping screws 262 engaging the frame 255. By loosening the screws 282, the angle brackets 219 and consequently the hanger arms 215 and pusher bar 215 may be adjusted with respect to 4trailing edges of the blanks of on the frame 294 and a roller 303 carried by a lever 304 pivoted on the/frame as at 305. Fast`with the lever 304 is an arm lil''engageable with the adjacent end ofthe link '291. When a cam similar to the cam^ |10 disclosed in Figures 5 and 6 is moved between the rollers 30| and 303, the lever 304 and arm \306`are rocked` so as to cause the arm 308 to push the link '291. thereby rocking the levers 29| and moving the blocks 294 away from their associatediixed gripper elements 281. f

A The embodiment shownin Figures 14, 15 and 16 may include a pusher bar similar to that incorporated in the construction shown in Figures 7 to 13 inclusive. Apusher bar 308 is connected to the frame 264 by hanger arms 309 secured by screws ,3|0 to angle brackets 3| I, in turn secured to the frame 284 by screws'3l'2. 'I he bar 808 is provided with spaced slots 3| 3 for receiving the a group carried by the grippingassembly 283.

Gripping assemblies as shown in Figures 14, 15

and 16 may be equipped with brushes 8 i4 for conthe frame 255. thus adapting the gripper assembly for holding blanks of different widths.

Another modiiled gripper assembly generally designated 283 and shown in Figures 14, 15 and 16 may be used in place of the assemblies |3| previously described. The gripper assembly 283 includes a cross frame member 284 provided at its opposite ends with blocks 285- connected by angle brackets 296 to the conveyor-chainsindicated at |30. When applied to the transfer conveyor C it is not necessary for the assembly 283v to be insulated from the chains |30. However, when applied to' the conveyors D and E the gripper assembly should be insulated. from the conveyor chains and for this purpose the blocks 295 may be formed of insulating material.

necting all of the blanks of. a group with a single bus bar when the blanks are being subjected to the cathodic cleaning or the electrolytic plating treatment.

The manner of performing the operations and the apparatus disclosed herein are representative f of the Apreferred apparatus for practicing the in-v vention, but it will be understood that changes may be made without departing from the invention as dened in the We claim:

1. In apparatus for preparing a plate blank for forming a can dy, treating bath means; conveyor means: means carried on said conveyor means i'or gripping an upper portiton of a blank and holding the blank suspended from said gripclaims.

ping means with a first edge portion of saidblank spaced below and completely exposed and unencumbered by said gripping means; means for reversing the gripping of said blank on the conveyor A plurality oi' iixed gripper elements 281 is secured to the cross lframe member 294 by screws 281e. Each gripper element 281 is formed with a clamping face 289 and a guide face 289. Prefermeans whereby when reversed the blank will be held by said gripping means and suspended therelfrom with a second edge portion of said blank spaced below and being completely exposed and unencumbered by said gripping means; means for driving said conveyor means; and means mounting the conveyor means to move a blank being conveyed in a path such that said first edge portion ofthe blank while completely exposed will be' aeoaeve meansl'; means for driving said conveyors in means lon oneof said conveyors for releasably holding ablank with a ilrst edge portion/thereof extended from said one of said conveyors and completely exposed and unencumbered by said first f holding means;lsecondmeans on the other of said conveyors lforYreleasablyholding saidvblank with a second `edge portion -thereof'extended from said other of said conveyors and completely exposed and unencumbered bysaid second holding means;

means for driving said conveyors in time with each otheriso -that the extended exposedjedge of av blank held by said ilrst releasable holding means is presented for engagement by said second releasable holding 'means; means operable upon s'aid ilrst and second releasable holding means when said blank is so presented for eecting releasing 'of the blank by said llrst holding means and en-f I.

gaging of the blank by said second holding means to transfer said blank from said rst conveyor to said second conveyor; and treating -bath means so positionedfwith respect to said conveyors that said first and second edge portions of the blank are projected while completely exposed` into said treating bath means respectively before and after transfer of said blank from'` said 'first conveyor -to said second conveyor. i

3. In a-pparatus for preparing a plate blank for forming a can-body, two adjacent conveyors; first gripper means on one of said conveyors for releasably holding a blank with a. rst edge portion thereof extended from said one of said conveyors and completely exposed and unencumbered by said rst gripper means; second gripper means on the other of said conveyors for releasably holding said blank with a second edge'portion thereof extended from said other of said conveyors and completely exposed andunencumbered by said second gripper' means; means for driving said conveyors in time with each other so that a blank held by said first gripper means is presented for engagement by said second gripper means; treat-ing bath means containing treating fluid so positioned with respect to said conveyors lthat .during travel of a blank rst on one conveyor and then Aon the other conveyor said edge portions will be projected successively and while completely exposed into said fluid; means for operating said first gripper means to 'grip said blank while said rst edge portion thereof is projected while completely exposed into said.

fluid Iand to release said blank when it is pre-l sented for engagement by said second gripper means; and means -for operating said second gripper means to maintain it -in non-gripping condition just prior to presentation of the blank and for actuating it to grip the presented blank and hold it gripped while said second edge portion is projected while completely exposed into said fluid. 4. In apparatus for preparing a plate blank for forming a can body, two adjacent conveyors; rst gripper means on one of said conveyors for releasably holding a blank with a first edge portion thereof extended `from said onezof said vconveyors and completely exposed and unencum-'oered by said iirst gripper means; second gripper means on the other of saidconveyors for releasably holding said time with each other solchen aebiankheld by said,

flrstgripper means/is presented lfor engagement by. said second gripper Jmeans; -treating bath means containingtreating fluid s o positioned with respect to said conveyors that during travel of a blank first on one conveyor-abil then on the other conveyor said edge portions will be projected suc cessively and while completely exposed into said fluid; lspring means for operating said first grip- .per ,means to grip said blank while said'first edgeportion is\approaching said treating bath means, while said rst edge portion4 is projected while` u completely exposed into said.f1uidan d while said blank -is being moved onufor presentation to saisi second gripper means;I cam mean-s for operating lsaid rst gripper means to release said blank ywhen it is so presented; spring means for operating said lsecond gripper means to grip a presented blank and h old it while saidY second edge portion is being moved to and projected while completely exposed into said uid; and cam means for operat- 'ing said second gripper means to non-gripping position -to 'receivea presented blank.

E?. In`apparatus for preparing a plate blank foflforming a can/body, Ian upper endless conveyor having top and bottom stretches; a lower endless conveyor having top and bottom stretches, the

bottom stretch of said upper conveyor extending generally parallel `to and above the top stretch of said lower conveyor; lower treating bath means under and adjacent 4the bottom stretch of said' lower conveyor; upper treating bath means under and adjacent the bottom stretch of ,said upper conveyor; lower holding means on said lower con.-

veyor for releasably holding a. blank with a nrs-t edge portion thereof extended and exposed; up-

per holding means on said upper conveyor for releasably holding said blank with :a second edge portion thereof extended; means mounting said lower conveyor to move `a blank held by said lower hodling means `and to project said blank first edge portion while exposed into` said lower treating bath means and then to withdraw said blank and present it for engagement by said 1upper holding means; means mounting said upper conveyorto' move said upper holding means to'receive a blank` presented by said lowerholding means and to move it to and .project said sec-ond edge portion into said upper treating bath means; means for operating said lower holding means to release a presented blank; Iand means for operating said upper holding means to enga-geand hold a presented blank. l

6. In apparatus for preparing a plate blank for forming a can body, an upper endless conveyor havingtop and bottom stretches; a lower endless conveyor having top and bottom stretches, the

blank with a second edge portion thereof extended from said other. of said conveyors and completely exposed and unencumbered by said second gripbottom stretch of said upper conveyor extending generally parallel to and above the top stretch of said lower conveyor; lower treating bath means under and adjacent the bottom stretch of said lower conveyor; upper treating bath means under and adjacent 'the bottom stretch of said upper conveyor; lower holding means on ysaid lower conveyor for releasabiy holding a blank with a first edge 'portion thereof extended; upper holding means on said .upper conveyor for releasably holding said blank with a second edge portion thereof extended and exposed; means mounting said lower conveyor t-o move a blank held-by -said lower holding means and to project said blank rst edge portion into said lower treating bath means and then to withdraw said blank and present it for engageupper treating bath means; Vmeans Vforoperatin said lower holding means to release a presented blank: means for operating said upper holdingmea-ns to engage andhold a presented blank; and

'adjustable --means for enacting variation oi.' the vertical spacing between one of said conveyorl lower stretches and the associated treatingibath means to thereby vary the depth to which the blank is projected intothe treating ilui'd. v 7. In apparatus for .preparing individual plate treating conveyor: releasable holding means on v Isaid conveyor for. holding a plate blank on said v conveyor for travel therewith to lthe treating means; another conveyor: other releasable holdin-g means on said other conveyor for holding a plate blank on said other conveyor; means mounting said conveyors -to operate with respective stretches thereof adjacent each other; means for driving sai-d conveyors tor said stretches to travel in the same general direction and at the same means to hold a blank until it is lpresented to the holding means on said treating conveyorjand then to release said blank; and means for conditioning the holding means on said treating conveyor to receive the presen-ted blank andto then hold the blank when `it is released by said other holding w. .M1 ToMxINs.

ALBERT c. LARKIN.

JOHN C. ANTHONY. 'OAKLAND K. ROSS.

RALPH M. MER/O.

REFERENCES CITED file 'of this patent: e

A UNITED s'rri'r'ausv Pa'r'aNrs blanks for forming can bodies. treating means; 'a 15 Number Name Date Norton Oct. 1, 1895 Goetz Apr. 10, 1900 Jueng'st Feb. 13, 1917 .Davoran Oct. 7, 1919 Freedman Jan. 2. 1923 Hollup Dec. 1, 1925 Hall -7.--- Jan. 24, 192B` Baker Dec. 22,1931 Bowman et al. May 2, 1933 Molyneaux Jan. 16, 1934 Yeager Mar. 6, 1934 Grupe Sept. 26, 1939 Todd Oct. 10,1939 Etchison May 7, 1940 Hallman Dec. 24, 1940 Hallman Dec. 24, 1940 Ger'oy May 20, 1941 Hopper Mar. 3, 1942 

